1. Field of the Invention
This invention relates to the field of data processing systems. More particularly, this invention relates to the control of cache memories within data processing systems.
2. Description of the Prior Art
It is known to provide data processing systems with cache memories so as to increase the processing speed by making access to data and/or instructions faster. Whilst cache memories improve processing speed, they have the disadvantage of consuming power in that data has to be copied from main memory to the cache memory, from where it can be further manipulated, rather than being directly taken from the main memory. Furthermore, when the data is no longer required in the cache memory, then it must be written back to the main memory if it has been changed so as to maintain consistency. Cache loads and cache flushes in this way are also relatively slow. A particular problem arises in circumstances, such as context switches, when large amounts of data must be flushed from a cache memory and then new data loaded into the cache memory. This is disadvantageously slow and consumes a disadvantageous amount of power.